The White House said Mr Obama would explicitly invoke "the experience in Massachusetts" as he calls on Republicans to accept his healthcare reform and stop "rooting for its failure".

"We have to wait to see what the president says in his speech but there clearly seems to be some symbolism involved in the venue choice given that Governor Romney signed the Massachusetts healthcare law in that very room," said Ryan Williams, a former Romney campaign spokesman.

At the 2006 bill signing ceremony, Mr Romney stood with what he called "partisans on both sides of the divide" next to banners reading: "Making History In Healthcare".

The White House did not respond to a request for comment on the decision not to invite Mr Romney to Wednesday's speech.

Mr Obama will speak as Kathleen Sebelius, the health and human services secretary, appears before Congress to explain the widespread problems with healthcare.gov, the Obamacare federal website.

The 2012 campaign rivals have met only once since November's election, sharing a lunch of turkey chili and salad at the White House three weeks after Mr Obama's victory.

Mr Romney also attended the President's speech at a memorial service for the victims of the Boston Marathon Bombing, calling it "superb".

His absence at Wednesday's speech is the latest step in an awkward dance between the former Massachusetts governor and his signature legislative achievement.

While Mr Romney's official governor's portrait features a copy of the healthcare law, a symbol of its place at the heart of his political legacy.

But as he faced conservative opponents during the Republican primaries he came under fire for his law's similarities to Obamacare and rarely spoke about it during the election.

Both laws centre around the idea of an individual mandate - a tax penalty designed to force people to buy health insurance.

Jonathan Gruber, an economist at MIT who worked on the Massachusetts law before heading to Washington to help with Mr Obama's reforms, said last year "at their core, the two laws are identical".